* {
    margin: 0;
    padding: 0
}

body {
    text-align: center;
}

#list {
    margin: 100px auto;
    border: 1px solid #000;
    border-left: none;
    border-top: none;
    overflow: hidden;
    background-size: cover;
}

#list li {
    list-style: none;
    float: left;
    border: 1px solid #000;
    border-right: none;
    border-bottom: none;
    box-sizing: border-box;
    background-size: cover;
}